Ignore *.img images in files folder
Ignore *.img images in files folder

Some (qcow) images have .img file name extension (e.g. Cirros).
Ignore such files in files/ folder too (as we already do
with .qcow2 and .gz images).

Change-Id: Iac8593b65205e25fd3f94244a136c584d9af8eab

olivierlemasle/devstack,samgoon/devstack,dtroyer/devstack,upadhyay-prashant/devstack,Mahito/devstack,bljgaurav/openstack-test,eharney/devstack,pacinete/devstack,liuquansheng47/devstack,NaokiMiyata/devstack,varunarya10/devstack,flavio-fernandes/devstack,prithivm/branch01,bljgaurav/openstack-test,nawawi/openstack,ozamiatin/devstack,costingalan/devstack,mmasaki/devstack,thomasem/devstack,noironetworks/devstack,atulpatil301/devstack,richliu/devstack,parul24/devstack,wenhuizhang/devstack,CloudServer/devstack,vishnugonela/devstack,eharney/devstack,herrsechs/devstack,LoHChina/devstack,ozamiatin/devstack,bswartz/devstack,costingalan/devstack,herrsechs/devstack,olivierlemasle/devstack,richliu/devstack,neerja28/Devstack_GlusterFS,HPCHub/devstack,avvocatodemarchis/devstack,bq-xiao/devstack,vsham20/devstack,pombredanne/devstack,varunarya10/devstack,pczerkas/devstack,liuquansheng47/devstack,mc2014/devstack,LoHChina/devstack,mssumanth/devstack,neerja28/Devstack_GlusterFS,prithivm/branch01,TwinkleChawla/devstack,vsham20/devstack,Mahito/devstack,flavio-fernandes/devstack,dtroyer/devstack,pombredanne/devstack,bq-xiao/devstack,wenhuizhang/devstack,openstack-dev/devstack,noironetworks/devstack,NaokiMiyata/devstack,bigswitch/devstack,atulpatil301/devstack,pczerkas/devstack,mc2014/devstack,group-policy/devstack,dirkmueller/devstack,andrewrothstein/devstack,thomasem/devstack,j4/devstack,CloudServer/devstack,pacinete/devstack,vishnugonela/devstack,rushiagr/devstack,upadhyay-prashant/devstack,bigswitch/devstack,samgoon/devstack,parul24/devstack,j4/devstack,dirkmueller/devstack,andrewrothstein/devstack,bswartz/devstack,openstack-dev/devstack,nawawi/openstack,rushiagr/devstack,group-policy/devstack,avvocatodemarchis/devstack,TwinkleChawla/devstack,mmasaki/devstack,HPCHub/devstack,mssumanth/devstack